The Undoing Project: A Friendship That Changed Our Minds

We understand a lot more about how we make decisions, the kinds of mistakes we seem to make and how we experience our world thanks to Danny and Amos, two grandsons of rabbis who lost their religion. These two men taught us that we are not natural statisticians and that our rules of thumb and gut feelings often lead us astray. They explained that we tell ourselves stories about people and things that are representative, that we make judgments based on insufficient data. For example, we often think that a handsome person is smarter. Or—take another example–have you ever decided that a three-year old is going to be a movie star or a doctor? How did you decide that this three-year old will find that profession appealing? Certainly not by using statistics. One of the first things Danny and Amos discovered is that even trained statisticians are not natural statisticians. We all make decisions based not on probability but on stories.

And there is more. It turns out we are very, very risk averse. We will do a lot to avoid feeling (or remembering the feel of) pain. Indeed, we are “happy” to experience (on the whole) more pain in order to remember less pain. And we will risk a lot to avoid losing things that we own or think we own. And by think we own, I mean we have an ingrained sense of what we are entitled to. There is a famous case study of monkeys who are all perfectly happy eating cucumbers so long as they all get cucumbers. But the minute some of them got bananas and some got cucumbers the monkeys who got cucumbers threw their cucumbers away in fury. They had no interest in being treated unequally. Humans are the same way. If you treat people equally, we’re OK with that; if you obviously advantage some people over some others, we get mad. Really mad. We know all this thanks to two Israeli psychologists.

When we make decisions when very little is or can be known, things are even worse. Then we use shortcuts called framing (the stories we tell to explain an event that often have little or nothing with the decision we have to make) and rules of thumb or gut feelings to make our choices. Not only that but we make decisions by referring to a story or something we recall that we think may be similar. On top of that, because we are really risk averse, we may well end up gambling in a manner that, if were able to look at our own actions from a statistical point of view, we would describe as reckless. But, as I mentioned before, we are not natural statisticians. All of this means that our decisions when little is known (say our decisions in the middle of the 2008 Crash) are uncertain at best.

All this probably sounds trite to you. At any rate, you probably heard all or most of these ideas already. They’re everywhere these days. In the New York Times op-eds and in school textbooks on everything from politics to economics to biology. But when Amos and Danny started, this idea of an irrational man was hardly trite at all. The prevailing idea of man at that time was that of a rational being. Smart people believed that we were able to know and order our preferences and if we made irrational decisions it was because strong emotions got in the way of our otherwise unbounded rationality. Amos and Danny turned that view of human nature upside down.

Amos Tversky and Danny Kahneman were as unlike as two people could be. Danny survived the Holocaust, hiding in various French safe houses, and that experience left him constantly doubting himself. A student’s mean review could throw him into a panic and if his ideas were not working out he would abandon them. Amos, on the other hand, was bold, brash, confident. He filled up the room. To this day, people remember his voice. The psychology they practiced was different too. Amos used formal, mathematical models to characterize and explain human behavior. Danny, Lewis tells us, was a poet who became a psychologist. So Amos and Danny were very different – but different in a way that complimented each other.

When these two unlikely people formed a kind of couple—became one mind—as they Danny it, they completely changed our understanding of ourselves. And yet it was the all-too human emotion of jealousy that drove them apart. They reconciled when Amos had only six months left to live.

This is a wonderful, human story about a friendship, about human nature, and about us and it is told by a wonderful story teller whose books I thoroughly enjoy. I highly recommend it.